Question

respiration is ______. taking in air, or breathing the use of oxygen by the cells the delivery of oxygen to the cells all of these

Explanation:

Respiration involves multiple aspects: breathing (taking in air), delivering oxygen to cells, and cells using oxygen for energy production (cellular respiration). So all the given options relate to respiration.

Answer:

D. all of these (assuming the last option is labeled D; if the original labels were different, adjust the identifier but keep the text "all of these")